Guinea’s diamond resources are related to Cretaceous age kimberlitic sills dykes and pipes which exploited major north trending structures in eastern Guinea. The country produced an estimated 600,000 cts in 2003. It is estimated that at least 800m of erosion has taken place in this area, meaning that most primary kimberlite pipes and dykes have been eroded away. Subsequent alluvials are located in most rivers draining north of this area.
Guinea has estimated diamond reserves of approximately 20 Mct. Diamonds are Guinea’s second largest export, after bauxite. With the ban of unlicensed ventures, foreign mining companies have begun to invest in the diamond sector. The Aredor Diamond Mine, located in southeastern Guinea, near Macenta, has produced some of the world’s most valuable diamonds, totalling more than 1.3 million carats at a value of US$377 million. Trivalence Mining Corporation through it’s wholly owned subsidiaries hold an 85% ownership interest in the Aredor mine and concession, which represents the most highly documented alluvial diamond reserves in Guinea. Aredor has historically produced large, high quality diamonds, the most recent being a 146 ct stone that fetched $1.9 million. Trivalence are currently bulk sampling (10 000t) the K23 kimberlite to determine economic potential. K23 has been drilled and has an elongate structure measuring 150m by 50m and has not been drill tested past 166m depth.
In order to further evaluate the potential of the K23 pipe or Aredor Kimberlite Project, Rio Tinto has signed a letter of intent with Trivalence wherer it can earn up to 58% of the project.
Searchgold Resources have acquired a 70% interest in local Ressources Mandala S.A.R.L., a Guinean company which owns 85% of the Mandala River permit that is located just south of Trivalence’s operations. The Mandala Permit has four identified alluvial deposits that has resources totalling 620 000 carats, according to previous companies that evaluated the area. During 2004 the company reported that a diamond parcel weighing 1670.23 carats and containing more than 7,500 diamonds all recovered from the Mandala III bulk sample was delivered to Antwerp.
Outside of the Aredor mine, Hymex Diamond corporation operates the only other commercial diamond operation, the alluvial operations at Kerouane, which have recovered 43,665 stones weighing 24,022 carats. On the Diani concession, Hymex have installed a 150-cubic-meter- per-hour capacity wash plant. Hymex also proceeded to install a 10,000-cubic-meter-per-month crushing plant at the Droubja kimberlite pipe. Proven reserves are estimated at 1.5 Mct (8 year life of mine) at its main alluvial operations.
Most of Guinea’s diamond production is produced by artisanal workers from alluvial workings. De Beers, through subsidiary Debsam, are also active in Guinea with the granting of several exploration licenses as well as completing a deal with the Guinea government to sell all diamond production through the CSO. Debsam are apparantly carrying out a regional sampling program, including the drill testing of several kimberlite pipes and dykes.
Dia Bras acquired several diamond concessions in Guinea. Systematic auger drilling, pitting and bulk sampling has outlined a resource of nearly 500 000 carats in more than 1.0 million square meters of gravel having an average grade of 0.50 carat per cubic meter on the Mandala Permit. Dia Bras intends to begin alluvial mining production shortly. Other concessions exhibit potential for alluvials as well as kimberlitic sources of diamond.
Trivalence continues to producecd good quality alluvial diamonds from its lease in southeastern Guinea but Rio Tinto has pulled out of the joint venture to search for kimberlite targets.
West African company Societe Alpha Plus and Pinnacle Resources have secured funding for their alluvial operations located on the Kentaye River that borders Mali. Upon securing funding (estimated at $400 000), Pinnacles can earn up to 40% of operating revenues generated by the operation.
Norwegian gold miner Guinor (formerly known as Kenor) has located several promising indicator mineral anomalies on its Dinguiraye concession – which hosts Kenor’s gold mining operations at Lero Karta and Fayalala.
Aredor, Bankole, Bidikoum, Boke, Dinguiraye, Droubja, Fria, Friguia, Halco aluminium mine, Karta mine, Kerouane, Kindia, Kiniero, Lero Karta, Mifergui, Mount Nimba, Sangaredi, Siguiri, Silidara, Simandou :[ View All ]
Hymex Diamond Corporation
Hymex Guine S.A. owns mineral rights on the Diani and Somolo alluvial diamond and gold concession covering 1,032 square km in Guinea, West Africa, as well as 422 sq km Milo site located 150 km from the Diani site.
Trivalence Mining Corporation of Canada
Trivalence have an 85% interest in the Aredor diamond mine in Guinea.